This invention relates to compressed, extruded, evacuated open-cell polymer foams and evacuated insulation panels containing them.
To significantly improve the performance of insulating systems, evacuated or vacuum panel technology is currently being evaluated by industry. The absence of air or gas in the panels affords the possibility of substantial enhancement of insulating performance.
A useful evacuated panel system is one employing a panel corestock of a rigid open-cell foam. The open-cell structure of the foam allows rapid and substantially complete withdrawal of gases from within the foam structure and the panel. The rigid foam matrix provides a corestock of substantial mechanical strength and performance.
Using open-cell foams in evacuated insulation panels, it has been possible to obtain R values of 10 to 15 per inch of thickness depending upon the evacuation or vacuum level, polymer type, cell size, density, and open cell content of the foam.
It would be desirable to achieve yet higher insulation capability (lower thermal conductivity) in evacuated panels employing open-cell foams.